Search results for "solubility"

Predicting Pharmacokinetics of Multisource Acyclovir Oral Products Through Physiologically Based Biopharmaceutics Modeling.

2021

Abstract Highly variable disposition after oral ingestion of acyclovir has been reported, although little is known regarding the underlying mechanisms. Different studies using the same reference product (Zovirax ®) showed that Cmax and AUC were respectively 44 and 35% lower in Saudi Arabians than Europeans, consistent with higher frequencies of reduced-activity polymorphs of the organic cation transporter (OCT1) in Europeans. In this study, the contribution of physiology (i.e., OCT1 activity) to the oral disposition of acyclovir immediate release (IR) tablets was hypothesized to be greater than dissolution. The potential role of OCT1 was studied in a validated physiologically-based biopharm…

Current Evidence, Challenges, and Opportunities of Physiologically Based Pharmacokinetic Models of Atorvastatin for Decision Making

2021

Atorvastatin (ATS) is the gold-standard treatment worldwide for the management of hypercholesterolemia and prevention of cardiovascular diseases associated with dyslipidemia. Physiologically based pharmacokinetic (PBPK) models have been positioned as a valuable tool for the characterization of complex pharmacokinetic (PK) processes and its extrapolation in special sub-groups of the population, leading to regulatory recognition. Several PBPK models of ATS have been published in the recent years, addressing different aspects of the PK properties of ATS. Therefore, the aims of this review are (i) to summarize the physicochemical and pharmacokinetic characteristics involved in the time-course o…

Bi3+doping in 1D ((CH3)3SO)PbI3: A model for defect interactions in halide perovskites

2022

The recently described monodimensional hybrid pseudo-perovskite ((CH3)3SO)PbI3 exhibits complete Pb2+/Bi3+ miscibility in the B site. Heterovalent substitution imposes that charge-compensating defects are introduced in the lattice as well. This paper reports the energetics of point defects and the interaction between charge-compensating defects that occur upon Bi3+ doping in ((CH3)3SO)PbI3. Periodic DFT simulations were employed to analyze the formation energy of Pb2+ vacancies, (CH3)3SO+ vacancies, iodide vacancies, or the insertion of interstitial iodide ions. Solid solutions with a large Bi3+ content were modeled considering different charge compensation defects (Pb2+ vacancies, (CH3)3SO…

Die Unauflöslichkeit der Ehe nach Amoris laetitia: Versuch einer theologischen Auseinandersetzung mit Bedenken mancher polnischer Moraltheologen

2020

The publication of Amoris laetitia initiated numerous discussions in the circles of theologians who focus on the question of the possibility of sacraments for remarried divorced couples. One of the fundamental theological questions in reference to marriage is the problem of the indissolubility. The apostolic exhortation shows no chapter or any point about the indissolubility of marriage but Amoris laetitia in numerous places talks about the problem of divorce and the stable indissoluble character of marriage. The article presents doubts of Polish moral theologians with regard to the indissolubility of marriage and attempts to explain and to answer them. The problem concerns two kinds of arg…

Environmentally Relevant Properties of All 209 Polychlorinated Biphenyl Congeners for Modeling Their Fate in Different Natural and Climatic Conditions

2009

The temperature dependence of physical properties and degradation lifetimes in the environment of all polychlorinated biphenyl (PCB) congeners (N = 209) were determined. For physical properties, the coefficients A and B in equations log(property) = A(property) − B(property)/T(K) were determined by thermodynamic and QSPR methods and compared with the results of independent methods in the literature. The coefficients Apl and Bpl for liquid state vapor pressure PL, As and Bs for solubility in water SW, Ah and Bh for volatility kH (or kH = PL/SW), and Aow and Bow for lipophilicity (KOW), stored in the database of the fate model program, allowed automatic temperature corrections for realistic fa…

Über die synthese von gewinkelten oligophenylenen höheren kondensationsgrades. 17. Mitteilung

1965

Es wird uber die Synthese von methylsubstituierten, ein- und zweifach m-gewinkelten Oligophenylenen bis zum Kondensationsgrad 14 berichtet. Durch Anwendung chromatographischer Methoden konnten die Verbindungen rein isoliert werden. Gewinkelte Oligophenylene besitzen bei vergleichbarer Struktur einen niedrigeren Schmelzpunkt und eine bessere Loslichkeit als p-Oligophenylene. The synthesis of methyl-substituted oligophenylenes with one or two meta-bonds up to a polymerisation degree of 14 is described. By application of chromatographic methods these compounds could be isolated free of impurities and homolog products. Angled oligophenylenes possess a lower melting point and a higher solubility…

Protein-Based Nanoparticles for the Delivery of Enzymes with Antibacterial Activity.

2018

Proteins represent a versatile biopolymer material for the preparation of nanoparticles due to their biocompatibility, biodegradability, and low immunogenicity. This study presents a protein-based nanoparticle system consisting of high surface PEGylated lysozyme polyethylene glycol-modified lysozyme (LYZmPEG ). This protein modification leads to a solubility switch, which allows a nanoparticle preparation using a mild double emulsion method without the need of surfactants. The method allows the encapsulation of large hydrophilic payloads inside of the protein-based nanoparticle system. Native lysozyme (LYZ) was chosen as payload because of its innate activity as natural antibiotic. The mild…

1989

A commercial low density polyethylene was irradiated by gamma irradiation at room temperature with different integrated doses and dose rates. The modifications induced in the material were studied by means of solubility and swelling measurements and related to structural modifications by calorimetric measurements. Results indicate that crosslinking prevails with respect to degradation at high dose rates and that the ageing phenomena occur essentially in the amorphous phase. Ein kommerzielles Polyethylen niedriger Dichte wurde bei unterschiedlicher integrierter Dosis und unterschiedlicher Dosisleistung bei Zimmertemperatur mit Gammastrahlung behandelt. Die Veranderungen des Materials wurden …

Tuning the upper critical solution temperature behavior of poly(methyl methacrylate) in aqueous ethanol by modification of an activated ester comonom…

2012

A statistical copolymer of methyl methacrylate (MMA) and pentafluorophenyl methacrylate (PFPMA, 6 mol%) exhibits upper critical solution temperature (UCST) behavior in aqueous ethanol solutions tunable by post-polymerization modification with different amines. The phase transition behavior of the obtained copolymers in aqueous ethanol was evaluated in detail. As expected, all copolymers reveal an upper critical solution temperature with 55 vol% or higher ethanol content. Furthermore, the solubility in aqueous ethanol of the copolymer can be increased by the introduction of hydrophilic moieties. When hydrophobic substituents are introduced a decrease in solubility was observed with low conte…

Polyaspartamide based hydrogel with cell recruitment properties for the local administration of hydrophobic anticancer drugs

2019

Abstract By exploiting the chemical versatility and the high water dispersibility of α,β-poly(N-2-hydroxyethyl)D,L-aspartamide, in this work, two different polymer derivatives were synthesized for the first time. Obtained macromolecules were characterized and used to produce hydrogels exploitable for the local release of hydrophobic anticancer drugs. The first derivative, bearing pendant β-cyclodextrins, was employed to solubilize tamoxifen, chosen as a model drug, and to produce a water soluble supramolecular complex, as evidenced through tamoxifen phase solubility studies. The second derivative, bearing pendant Cyclo(Arginine-Glyicine-Asparagine-D-Phenilyalanine-Cysteine) peptide moieties…